Kamen Rider Agito: Marching Into the Depths
by Gundam Kaiser
Summary: He knew, almost right from the beginning, that it was a hopeless battle. But... even knowing that it would be useless, he still chose to fight. And so it was that he marched into the abyss of war... Self-insert, crossover of Kamen Rider Agito and Devilman. Rated M because, well... Devilman.
1. Prologue

**This is inspired by StrangerDenB4's SI fic, "Kamen Rider Kuuga: Rising Unto the Stars". It's a crossover of KR Kuuga and the Pretty Cure franchise, and it's a really fun read. You should all give it a shot. As for _this_ fic, it's an Agito crossover with Devilman. Specifically the original manga, but occasionally with some elements of the OVA. There will probably also be a few characters from some of Go Nagai's other works making appearances as well.**

* * *

Despair is courage. Apathy, resolve. Nihilism, the appreciation of life in all its splendor.

This... is a tale of a disillusioned man, whose spirit was crushed beneath the weight of his own ideals. A nihilist, who desperately looks for hope and justice where he believes there is none. An idealistic fool, who can only take pride in meaningless things.

This tale, too, is meaningless - what you do with it is of no consequence.

But then, if there is no consequence, then that means you're free to do with it as you will. Stay and read it? Ignore it? Mock it? It doesn't matter, so just do whatever pleases you.

If you want to, you may even choose to enjoy it.

* * *

The year is 200X. The locale, metropolitan Japan.

Our narrative features on a young male in his early 20s, very clearly _not_ Japanese. Hair's a mess, hasn't shaved in a couple of days, and the default expression beneath those glasses is a surly one. He's a bit out of shape compared to his days as a teenager, his endurance and agility having waned enough to be a sore point with him.

With this information, an introspective person might assume a bitter and/or apathetic introvert, who hates dealing with people in any shape or form. Alternately, given the paunch at his stomach but the slightly above-average definition and musculature in his arms, perhaps the more likely first impression might be that he's some kind of American tavern-trash that got lost on his tour.

In the first case, they'd be partly wrong - get him on a topic he likes, and he'll happily chat with a total stranger for _hours_. In the second case, they'd be entirely wrong - he despises alcohol, claiming that he'd visit a children's pharmacy if ever he felt like drinking cough syrup, and has never set foot in a drinking establishment in his life.

Really, his attire doesn't do him much service either. Partly-ripped-up jeans and worn-out sneakers, all of it black or near-black. The comparatively nice button-up shirt can only do so much in making him presentable.

After a moment or two, he pulls out his phone - not to contact anyone, but to check the time with it, as he neglects to ever wear and keep a watch. "It's been another ten minutes," he grumbles, and then pulls up a list of contacts. Fumbling slightly - he's never cared much for texting, but his inexplicable preference for flip-phones only serves to make it _less_ convenient than it could otherwise be - he types in a simple message:  ETA?

No sooner than he can send it, he collapses to one knee, grimacing in pain. He doesn't utter a sound, though - he's "trained" himself on countless stubbed toes, careless collisions with furniture, and other clumsy accidents to the point of remaining silent at times in the face of sudden pain.

His vision fades in and out, a blinding light stabbing through his mind, making it hard for him to think, as a single compulsion begins to cover his consciousness.

"Dammit all, not _now..._ "

Despite his complaints, he turns in a seemingly random direction, and starts running - either unwilling or unable to resist the mental compulsion placed upon him.

After a few minutes, he arrives in a deserted back alleyway, where an unfortunate victim has been half-eaten by what can only be described as a demon, straight from the bowels of Hell itself.

Doubtless it took the form of a female, but presently it's quite the grotesque one. Bent over backwards on all four limbs, the forearms having become legs in their own right; the head having split open, with great horrible teeth extending from each side.

On top of its body, where a woman's breasts would be, have extended into gnarled and spindly arms, with end with grasping claws.

The creature is, truly and absolutely, like something born out of a nightmare. It is the kind of sight that, over the past few weeks, our protagonist has become used to.

A bright, blinding light erupts from his waist, at the point where a belt buckle would be.

 **BGM: Kamen Rider Agito opening song**

As if in a trance, he strikes a pose and says, "Transform." A momentary distortion of light, and in his place is an armored figure.

Kamen Rider Agito.

With a hot-blooded shout, the figure attacks his hellish foe with a kick to its head.

It is the beginning of yet another meaningless battle.

Even if he defeats the enemy before him, he knows that the world around him is doomed with an inescapable fate.

Before he arrived in Japan, and began these meaningless battles... If he were asked about the future, he would freeze up in terror at the uncertainty and vagueness of it all.

But not here, not in this world. Indeed, it is _because_ of the inevitable fate of armageddon, that he feels free from consequences.

Because he thinks his actions won't matter at all in the grand scheme of things, that gives him the freedom to do what he wishes.

It is true, certainly, that he has trouble communicating with people except in the context of popular media.

It is true, that his own beliefs, once they clashed with reality, drove him to stop believing in anything.

He is the kind of negative person who can't truly believe anything positive of himself, even as a joke.

But for all of this, one other thing is also true.

His hopes, and dreams, even if he thinks them to be futile... they are all of "justice".

In this world, he believes he can do what he wants without consequence, because everything will be destroyed.

Because everything will be destroyed one day, it must be enjoyed and wondered at while it still lasts.

Many people would use this pessimistic logic to justify working deeds of evil, but this person... this incredibly bizarre person...

If he had his way, he'd rather try and be a hero.

* * *

 **To be continued...?**


	2. Chapter 2

**Got some nice feedback for the last chapter. Actually got slightly more than I was expecting, given what I'm working with here. Main thing to add right now is that I'm pretty much mining other Go Nagai works for the supporting cast, with some emphasis on the Mazinsaga.**

* * *

"Kuuuuoooooaaaahhhhh!"

With that hot-blooded yell, Agito unleashed his finishing move and destroyed the demon with one punch, causing it to explode.

A moment later, the amor faded, and in Agito's place stood the American from before. Scowling at the bloody mess the demon had left of its human meal, the man muttered, "I hate this crap."

He ran one hand through his hair in an attempt to relieve some stress, while flipping open his phone to tip off the police about the murder with his other hand. _I've seen this kind of bloody carnage so many times now_ , he thought to himself, _that it doesn't really even bother me anymore._

"Ah, yes, um, I'm calling to report a murder in the alleyway between..."

 _I've become desensitized to it. But, the fact that I can look on this and no longer be infuriated by it... isn't that a bad thing?_

The year is 200X. The locale, a metropolitan city in Japan. This concrete jungle, unbeknownst to its populace, has become the focal point of a war for mankind's very survival.

Flipping his phone shut with a sigh, our protagonist muttered, "And the home team's getting _wrecked_..."

* * *

Jogging at full tilt, I eventually made it back to the stadium. Completely, totally out of breath. Dammit, I hate this body. Granted, it's my own damn fault for not taking care of it. Just what a lazy bastard like me deserves.

"And here we thought you were anxious for _us_ to get here."

The woman's tone is playful, but... dammit all, I _despise_ it when people tease me. Can't help but to fix the bespectacled girl with the kind of glare you see all the time in Stanley Kubrick movies.

A second voice. "I thought you were a _Spidey_ fanatic. So where'd all the _venom_ come from?"

I slowly swivel toward the latest person to quip at my expense, offering them the very same glare. I'm recovering from one hell of a sore throat, so my voice is still a bit raspy. "Screw you too, Miki."

A third voice, this time a male. "Nah, Akira's the only one who gets to tap that."

I abruptly force myself to stand perfectly upright again and breathe at a more proper, measured pace. I wanna see this.

Yep, sure enough, a brunette shouts in outrage and slaps the shit out of the guy who said that. "TETSUYA!"

Standing in front of me, expressing amusement at the bullshit that is this conversation, are some people I hang out with. I don't really know them all that well personally, and I think that holds true the other way around too, but... if they call me their friend, then I guess it's okay for me to say the same thing?

They are... oh, hell, I'll be blunt. They're the main characters of the Mazinsaga. Koji Kabuto and his girlfriend Sayaka Yumi. Koji stands slightly shorter than myself, and is a hotheaded but righteous-minded youth. ...I call him a youth, but the fact is that I'm only three years older than he is. As for Sayaka, well... rockin' that archetypical "soft tsundere" personality as always.

A few years older than those two, and about my own age, are Tetsuya Tsurugi and Jun Honoo. Tetsuya, a muscular guy who's even taller than me - and I'm a solid six-foot-two, when I stand up straight - acts like kind of an ass from time to time, but he's got sort of a "big brother" vibe about him. As for Jun, she's as cool as she is hot. Far as I'm concerned, she's kind of like the mom I never had. ...actually, no, the more accurate statement is "better than the mom I hardly _did_ have".

And then finally, Miki Makimura. Quite possibly the most important girl in the world. ...not really on her own merits, but because of how much she means to Akira Fudou, better known around the world as Devilman.

...I'm sure that putting it bluntly like that sounds horribly, horribly sexist, but hey. I call the situation like I see it. Now, having said that, I actually do think Miki's pretty cool. A couple of muggers went after her the other day, so she went and pulled out _a home-made switchblade knife on 'em_. It was awesome. ...although, it probably sounds less so in my telling of it. Honestly, you had to _be_ there.

"What, did you flash back to some game you played as a kid again, or something?"

"Nah, just enjoying watching Sayaka slap the shock out of Tetsuya."

...'shock?' Really? Did I really just say that? ...Maybe I should lay off the _Spider-Man 2099_ comics for a while...

In any case, you're probably wondering how the hell I got into this situation.

...eh, it's the same kind of story you've heard a million times. Fresh college grad fires up the internet on his umpteenth attempt at finding a job, is suddenly face-grabbed by the Go Nagai version of Archangel Lucifer through the computer screen, and forcibly dragged through the LCD fourth wall into the middle of a fight between Devilman and some random devil mook.

Cue the mind-splitting headache, followed by a trance-like transformation into Agito.

...yeah, I wish _I_ had some better details about it too, but whenever I become Agito, my memories and my perception get distorted as all hell. Although given that I'm still physically intact, and the other guy seems to be fine as well, it's probably safe to conclude that Agito and Devilman didn't wind up killing each other. ...although with these screwy memories, for all I know they could still have made a decent go at it.

...but then, if I somehow awakened as an Agito, then what the hell is going on? I haven't - as far as I know - encountered any Unknowns/Lords, and the Seed of Agito seems to be driving me to fight Devils. Which, _really_ doesn't make a lot of sense to me, since the Overlord of Light only gave humans the potential to become Agito as a dying "fuck you" to the Overlord of Darkness, who liked his humans the same way he liked his dinosaurs - evolutionary potential LIMITED.

Humans being murdered and devoured by demons... wouldn't that be just as much of a revenge against the OOD as evolution into Agito is?

And if the Seed of Agito habitually bodyjacks me into fighting devils, why would it not send me into combat against Devilman? ...but then, Devilman can also be considered an "evolution" - or, alternately a "corruption" - of humanity, so that particular detail actually does appear to fit back into the puzzle as I've always understood it.

...but then, is the Overlord of Light _really_ the source of my powers as an Agito? I mean, if Lucifer was able to drag me through the fourth wall, from _his_ side of it, then wouldn't it be a trivial thing for him to endow me with some manner of equivalent to the Seed of Agito?

...but if that's what happened, Regis, then the million-dollar question is, 'Why-

"HOLY SHIT, DID THAT GUY JUST DO A FLYING HEADBUTT OFF THE TOP ROPE?! ON A GUY THAT ISN'T EVEN IN THE RING?!"

"Yes," Jun replies with some sass and no small degree of amusement, "that's exactly what he just did."

Oh, Japanese Professional Wrestling, you never cease to stun and amaze me.

* * *

Another day, another devil doing its dirty deeds, another stabbing pain inside my head prompting me to turn into a superhero and kill it.

The evening wind blows through, sending a chill down my spine.

...no, wait. This dread I'm feeling... it's more than just the weather or my general sense of anxiety. Something... _bad_ is going to happen.

A female voice, barely kept aloft by the wind. "You should hide yourself, O lovely moon. ...unless you wish to see something truly horrible."

...no. No no no no no. I recognize that phrase. And now the moon's going behind some cloud cover? Shit, Silene's about to make her move, isn't she?

But then, does that really concern me? If I don't go and involve myself, Akira should be able to protect the Makimuras well enough, and Devilman's going to survive the night while Silene and Caim won't.

...but then, those two weren't like most of the other demons. They had... sentiment. Honor. It might be possible to get them to change sides...

"GAAAAH!"

Blinding, white-hot pain inside my skull. It seems the decision is being made for me. As if of its own accord, my mouth moves and says, "Transform!"

* * *

 **To be continued...?**


End file.
